Understanding Rarp; Preparing To Configure The Ip Address And Default Gateway - Cisco WS-C2948G-GE-TX Configuration Manual

Preparing to Configure the IP Address and Default Gateway

Table 3-1
Code
51
52
61
66
If a BOOTP response is received from a BOOTP server, the switch sets the in-band (sc0) interface IP
address to the address that is specified in the BOOTP response.
If no DHCPOFFER message or BOOTP response is received in reply, the switch rebroadcasts the request
using an exponential backoff algorithm (the amount of time between requests increases exponentially).
If no response is received after 10 minutes, the sc0 interface IP address remains set to 0.0.0.0 (provided
that RARP requests fail as well).
If you reset or power cycle a switch with a DHCP- or BOOTP-obtained IP address, the information
learned from DHCP or BOOTP is retained. At boot up, the switch attempts to renew the lease on the IP
address. If no reply is received, the switch retains the current IP address.

Understanding RARP

With RARP, you map the switch MAC address to an IP address on the RARP server. The switch retrieves
its IP address from the server automatically when it boots up.
The switch broadcasts ten RARP requests after all of the switch ports are online. If a response is
received, the switch sets the in-band (sc0) interface IP address to the address that is specified in the
RARP response.
If no reply is received, the sc0 interface IP address remains set to 0.0.0.0 (provided that DHCP requests
fail as well).
If you reset or power cycle a switch with a RARP-obtained IP address, the information that is learned
from RARP is retained.
Preparing to Configure the IP Address and Default Gateway
Before you configure the switch IP address and default gateway, obtain the following information, as
appropriate:
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Catalyst 4500 Series, Catalyst 2948G, Catalyst 2948G-GE-TX, and Catalyst 2980G Switches Software Configuration Guide—Release 8.2GLX
3-4
Supported DHCP Options (continued)
Option
IP address lease time
Option overload
Client-identifier
TFTP server name
IP address for the switch (sc0 and me1 interfaces only)
Subnet mask/number of subnet bits (sc0 and me1 interfaces only)
(Optional) Broadcast address (sc0 and me1 interfaces only)
VLAN membership (sc0 interface only)
SLIP and SLIP destination addresses (sl0 interface only)
Interface connection type:
– In-band (sc0) interface
Configure this interface when assigning an IP address, subnet mask, and VLAN to the in-band
management interface on the switch.
Chapter 3 Configuring the Switch IP Address and Default Gateway
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